1. Field of the Invention
The invention relates generally to communication systems, and more particularly to selecting a channel in a multichannel communication network based on channel quality.
2. Discussion of Related Art
In today""s information age, there is an increasing need for high-speed communication networks that provide Internet access and other on-line services for an ever-increasing number of communications consumers. To that end, communications networks and technologies are evolving to meet current and future demands. Specifically, new networks are being deployed which reach a larger number of end users, and protocols are being developed to utilize the added bandwidth of these networks efficiently.
One technology that has been widely deployed and will remain important in the foreseeable future is the multichannel communication network. A multichannel communication network is one that supports a number of separate communication channels. Typically, each communication channel is one of a number of frequency bands carried over a shared physical medium such as a hybrid fiber-optic/coaxial cable (HFC) network or wireless network.
One type of multichannel communication network includes a single primary station coupled to a plurality of secondary stations over the shared physical medium in a point-to-multipoint configuration. Typically, the primary station transmits to the secondary stations over a single communication channel, and the secondary stations transmit to the primary station over one or more shared communication channels. The primary station controls the secondary station transmissions using control messages that authorize a specified secondary station or group of secondary stations to transmit on a specified communication channel.
One desirable feature of such a multichannel communication network is the ability to dynamically switch the secondary station transmissions among the shared communication channels (often referred to as xe2x80x9cfrequency agilityxe2x80x9d or xe2x80x9cfrequency hoppingxe2x80x9d). Frequency agility allows the primary station to spread the secondary station transmissions across multiple channels to control network congestion (often referred to as xe2x80x9cload balancingxe2x80x9d). Frequency agility also allows the primary station to avoid channels that are unusable due to excessive distortion or equipment failure.
In order to support frequency agility, the primary station typically maintains a list of available communication channels. When the primary station needs to select a communication channel, either for load balancing or to avoid an unusable channel, the primary station""selects one of the available communication channels from the list. At that time, the primary station has no way of knowing whether or not the selected communication channel is usable. If the selected communication channel is in fact unusable, any scheduled transmission on the selected communication channel will be lost, and the primary station will be forced to select another available communication channel. Therefore, a system, device, and method for selecting a communication channel based on channel quality is desirable.